Research And Application Of Zinc-ion Hybrid Supercapacitor

It is of great significance for the development of modern society to construct and manufacture a new type of electrochemical energy system with high power and energy density,long cycle life and green pollution-free.The traditional energy storage equipment mainly includes batteries and supercapacitors,but their defects limit the further development,such as low power density and poor cycle stability of batteries and the low energy density of supercapacitors.Supercapacitor-battery type hybrid supercapacitor?SBTHSC?is a typical energy storage device constructed with a high-rate capacitive-type electrode and a large-capacity battery-type electrode,which has attracted wide attention because of its advantages of both battery and supercapacitor.As one of theses SBTHSCs,aqueous zinc-ion hybrid supercapacitors?ZHSCs?has become one of the most popular research due to their unique merits such as high performance,cheapness,safety and environmental friendliness.The development of ZHSC depends not only on the appropriate electrode materials,but also on the construction of superior energy storage system.Therefore,more in-depth research on these two aspects is needed to further improve the performance of ZHSC to meet the needs of people in the field of energy storage.The specific contents of the two works in this paper are as follows:?1?In this work,the MXene-reduced graphene oxide?MXene-rRO?aerogels are prepared with the frameworks of porous three-dimensional?3D?rRO aerogels.The MXene-rRO aerogel with unique porous skeleton structure not only to largely prevent the stacking of MXene nanosheets,but also endowed the aerogels with high hydrophilicity and excellent conductivity.For the first time,the porous 3D MXene-rRO aerogel cathode,zinc foil anode and 2 M ZnSO₄electrolyte were used to prepare MXene-rRO//ZnSO₄//Zn ZHSC.As a result,the outstanding electrochemical performances of the MXene-rRO2//ZnSO₄//Zn ZHSC are exhibited with a maximum specific capacitance of 129 F g^-1(0.4 A g^-1)and a high energy density of 35 Wh kg^-1(280 W kg^-1).More importantly,the capacitance retention is still above 95%of its initial capacitance after 75,000 charge and discharge cycles at the current density of 5 A g^-1.This work provides a new thinking for developing high performance ZHSCs with other 3D porous cathode materials.?2?Compared with the first work,this work innovates the device structure of ZHSC.A new two-dimensional layered titanium disulfide?de?intercalation battery-type electrode takes the place of the traditional zinc foil electrode as anode,and then it is assembled with the active carbon capacitor-type cathode and 2 M ZnSO₄ electrolyte to prepare TiS₂//ZnSO₄//AC ZHSC.It is worth mentioning that the TiS₂//ZnSO₄//AC ZHSC shows a high specific capacitance of249 F g^-1(0.2 A g^-1),superior power density of 3600 W kg^-1(35 Wh kg^-1)and high energy density of 112 Wh kg^-1(180 W kg^-1).Furthermore,after 5000 long cycles(current density of 2A g^-1),the TiS₂//ZnSO₄//AC ZHSC also demonstrates excellent cycle stability with high capacitance retention of 92%.In this work,a new concept is proposed to design the next-generation high-performance ZHSCs by using the?de?intercalation battery-type anode instead of the zinc foil anode.